SUPPLEMENTARY INFORMATION

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1 SUPPLEMENTARY INFORMATION doi:./nchem.9 Catalytic dehydroaromatization of n-alkanes by pincer-ligated iridium complexes Ritu Ahuja, Benudhar Punji, Michael Findlater, Carolyn Supplee, William Schinski, Maurice Brookhart *, Alan S. Goldman * Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 99, USA Department of Chemistry, Monmouth University, West Long Branch, New Jersey, USA Chevron Research and Technology Co., Chevron Way, Richmond, CA, 9, USA. *To whom correspondence should be addressed. brookhar@ .unc.edu; alan.goldman@rutgers.edu nature chemistry Macmillan Publishers Limited. All rights reserved.

2 supplementary information doi:./nchem.9 Supplementary Information Table of Contents. Gas chromatographic analysis methods. S. General methods and gas chromatographic analysis of solvents S. Synthesis of ( ipr PCOP)Ir(η -C H ) () S9. Synthesis of -((diisopropylphosphino)methyl)phenol () S9. Synthesis of ipr PCOP-H ligand precursor () S9.. Synthesis of ( ipr PCOP)IrHCl (9) S.. Synthesis of ( ipr PCOP)Ir(η -C H ) () S. Synthesis of ( ipr Anthraphos)Ir(η -C H ) () S. Data for dehydroaromatization reactions S. Dehydroaromatization of n-hexane. S. Dehydroaromatization of n-octane. S. Dehydroaromatization of n-decane S. Dehydroaromatization of n-dodecane S. References S nature chemistry Macmillan Publishers Limited. All rights reserved.

3 doi:./nchem.9 supplementary information. Gas chromatographic analysis methods. GC analyses (FID detection) were performed on either a Thermo Electron Corporation Focus GC instrument fitted with fused silica capillary column ( m length x. mm ID x. µm film thickness) or an Agilent Technologies GC instrument, also fitted with fused silica capillary column ( m length x. mm ID x. µm film thickness), using the following GC methods: GC Method Thermo Electron GC Detector: FID Starting temperature: C Time at starting temp:. min Ramp: C/min up to C with hold time = min Ramp: C/min up to C with hold time = min Flow rate (carrier): ml/min (He) Split ratio: Inlet temperature: C Detector temperature: C GC Method Agilent Technologies GC Detector: FID Starting temperature: C Time at starting temp: min Ramp: C/min up to C with hold time = min Flow rate (carrier): ml/min (He) Split ratio: Inlet temperature: C Detector temperature: C nature chemistry Macmillan Publishers Limited. All rights reserved.

4 supplementary information doi:./nchem.9. General methods and gas chromatographic analysis of solvents. All manipulations were conducted under an argon atmosphere either in an argonfilled glove box or using standard Schlenk techniques. Anhydrous solvents were purchased from Aldrich and degassed with argon and stored in the glove box. TBE and all n-alkanes used were purchased from Aldrich and distilled from NaK alloy. All n-alkanes were determined by GC to be greater than 99% pure. The TBE was found to have a substantial amount (ca. %) of,-dimethyl--butene impurity, and a much smaller amount of,-dimethyl--butene impurity (ca..%), the concentrations of which did not change significantly over the course of the reaction. In view of the surprising formation of in the case of the alkanes of carbon number >, particular care was taken to analyze the TBE and n-alkanes for or species which might act as precursors to. Of particular note, no significant concentrations ( mm or greater) of n-hexane, -hexene, trans--hexene, trans--hexene,, cyclohexane, cyclohexene,,-cyclohexadiene, or any compounds of similar GC retention time were present in the TBE, n-octane, n-decane, or n-dodecane in detectable concentrations (while n-hexane contained no detectable cyclic C compounds). The limit of detection was established at significantly less than.% (ca.. mm) by the addition of the authentic C linear and cyclic hydrocarbons (.% v:v) to the TBE and n- alkanes. These C compounds are all very well separated from the TBE and, of course, from the higher n-alkanes (while cyclic C compounds are very well separated from n- hexane). For example, retention times using Method are as follows: TBE,. m;,- dimethylbut--ene,. m;,-dimethylbutane,.9 m; -hexene,. m; trans-- hexene,. m; trans--hexene,.9 m; n-hexane,.9 m;,-dimethylbut--ene,. m;,. m; cyclohexane,. m; cyclohexene,. m; n-octane,.9 m; n- decane,. m; n-dodecane,. m. The regions of the GC traces corresponding to the retention times of the linear and cyclic C hydrocarbons, with and without the authentic C samples added to the TBE and n-alkanes, is shown in Figure S. -(bromomethyl)phenol and HP i Pr were prepared as described previously. All other reagents were obtained from commercial sources and used as received. NMR spectra were recorded on - or -MHz Varian spectrometers. H NMR spectra are nature chemistry Macmillan Publishers Limited. All rights reserved.

5 doi:./nchem.9 supplementary information referenced to residual proteo solvent while P{ H} NMR chemical shifts are referenced to an external standard, Me P in mesitylene-d solvent (δ -. ppm) in a capillary tube. Figure S GC traces obtained from analysis of TBE showing the region of retention times (GC Method ) of linear and cyclic C hydrocarbons (. m. m). Trace (bottom): TBE used for dehydroaromatization experiments (with,-dimethylbut--ene impurity identified). () Same solution after addition of.% (v:v) each of authentic samples of representative linear and cyclic C hydrocarbons: -hexene, trans--hexene, trans--hexene, n-hexane,, cyclohexane, cyclohexene and,-cyclohexadiene. nature chemistry Macmillan Publishers Limited. All rights reserved.

6 supplementary information doi:./nchem.9 Figure S GC traces obtained from analysis of n-octane showing the region of retention times (GC Method ) of linear and cyclic C hydrocarbons (. m. m). Trace (bottom): n-octane used for dehydroaromatization experiments. () Same solution after addition of.% (v:v) each of authentic samples of representative linear and cyclic C hydrocarbons. nature chemistry Macmillan Publishers Limited. All rights reserved.

7 doi:./nchem.9 supplementary information Figure S GC traces obtained from analysis of n-decane showing the region of retention times (GC Method ) of linear and cyclic C hydrocarbons (. m. m). Trace (bottom): n-decane used for dehydroaromatization experiments. () Same solution after addition of.% (v:v) each of authentic samples of representative linear and cyclic C hydrocarbons. nature chemistry Macmillan Publishers Limited. All rights reserved.

8 supplementary information doi:./nchem.9 Figure S GC traces obtained from analysis of n-dodecane showing the region of retention times (GC Method ) of linear and cyclic C hydrocarbons (. m. m). Trace (bottom): n-dodecane used for dehydroaromatization experiments. () Same solution after addition of.% (v:v) each of authentic samples of representative linear and cyclic C hydrocarbons. nature chemistry Macmillan Publishers Limited. All rights reserved.

9 doi:./nchem.9 supplementary information. Synthesis of ( ipr PCOP)Ir(η -C H ) ().. Synthesis of -((diisopropylphosphino)methyl)phenol (). A mixture of - (bromomethyl)phenol (. g,. mmol) and HP i Pr (. g,. mmol) in degassed acetone ( ml) was heated to reflux for h and then stirred at room temperature overnight. The mother liquor was decanted from the white waxy precipitate and the precipitate dried under vacuum. The precipitate was treated with a saturated solution of NaHCO ( ml) and stirred at C for h. After cooling to room temperature, the mother liquor was removed via cannula transfer and the white precipitate was dried under vacuum. This product was extracted with THF ( ml x ) and the combined solutions were evaporated under vacuum to obtain a waxy orange color product. Yield:. g (%). H NMR ( MHz, CDCl ): δ. (t, J HH =. Hz, H, Ar-H),. (d, J HH =. Hz, H, Ar-H),. (s, H, Ar-H),. (d, J HH = 9. Hz, H, Ar-H),. (s, H, OH),. (d, J PH =. Hz, H, CH ),. (sept of d, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),.-.9 (m, H, CH(CH ) ). P{ H} NMR (. MHz, CDCl ): δ. (s). C{ H} NMR (. MHz, CDCl ): δ. (s, Ar-C),.9 (d, J PC =. Hz, Ar- C), 9. (s, Ar-C),. (d, J PC =. Hz, Ar-C),. (d, J PC =. Hz, Ar-C),. (d, J PC =. Hz, Ar-C), 9. (d, J PC =. Hz, CH ),. (d, J PC =. Hz, C, CH(CH ) ), 9. (d, J PC =. Hz, C, C(CH ) ), 9. (d, J PC =. Hz, C, C(CH ) )... Synthesis of ipr PCOP-H ligand precursor (). A solution of - ((diisopropylphosphino)methyl)phenol (. g,. mmol) in THF ( ml) was added dropwise to a suspension of NaH (. g,. mmol) in THF ( ml) and the reaction mixture was heated to reflux for. h. After cooling to room temperature, a solution of chlorodiisopropylphosphine ( i Pr PCl) (. g,. mmol) in THF ( ml) was added nature chemistry 9 Macmillan Publishers Limited. All rights reserved.

10 supplementary information doi:./nchem.9 dropwise via cannula and the resultant reaction mixture was heated to reflux for h. The solvent was then removed under vacuum and the product was extracted with pentane ( ml x ). The combined pentane solutions were taken to dryness under vacuum to obtain a viscous liquid product. Yield:. g (%). H NMR ( MHz, C D ): δ. (s, H, Ar-H ipso),.-. (m, H, Ar-H),.9 (d, J HH =. Hz, H, Ar-H),. (s, H, CH ),. (sept. of d, J HH =. Hz, J PH =. Hz, H, OPCH(CH ) ),. (sept. of d, J HH =. Hz, J PH =. Hz, H, PCH(CH ) ),. (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ),.9-. (m, H, CH(CH ), H, CH(CH ). P{ H} NMR (. MHz, C D ): δ. (s, O-P),. (s, CH -P). C{ H} NMR (. MHz, C D ): δ. (d, J PC =. Hz, Ar-C),. (d, J PC =. Hz, Ar-C), 9.9 (s, Ar-C),. (dd, J PC =.9 Hz, J PC =. Hz, Ar-C),. (dd, J PC =. Hz, J PC =. Hz),. (dd, J PC =. Hz, J PC =. Hz, Ar-C),. (d, J PC =. Hz, CH ), 9. (d, J PC =. Hz, C, C(CH ) ),. (d, J PC =. Hz, C, C(CH ) ),. (d, J PC =. Hz, CH(CH ) ), 9. (d, J PC =. Hz, C(CH ) ),. (d, J PC =. Hz, C(CH ) ),. (d, J PC =.9 Hz, C(CH ) )... Synthesis of ( ipr PCOP)IrHCl (9). A mixture of ipr PCOP-H (;. g,. mmol) and [Ir(,-cyclooctadiene)Cl] (. g,. mmol) in toluene ( ml) was heated to reflux for h at C under an H (g) atmosphere. After cooling the reaction mixture to room temperature, the mother liquor was evaporated under vacuum. The product was extracted with pentane ( ml x ) and combined pentane solutions were evaporated to obtain an orange-red crystalline product. Yield:. g (%). Anal. Calcd for C 9 H ClO P Ir: C,.; H,.; Cl,.. Found: C,.; H,.; Cl,.. H nature chemistry Macmillan Publishers Limited. All rights reserved.

11 doi:./nchem.9 supplementary information NMR ( MHz, C D ): δ.-.9 (m, H, Ar-H),. (d, J HH =. Hz, H, Ar-H),. (dd, J HH =. Hz, J PH = 9. Hz, H, CH ),. (dd, J HH =. Hz, J PH = 9. Hz, H, CH ),. (sept. of d, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),. (sept. of d, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),.-. (m, H, CH(CH ) ),.9 (sept. of d, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),.9 (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ),. (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ),. (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ),.-. (m, H, CH(CH ), -. (t, J PH =. Hz). P{ H} NMR (. MHz, C D ): δ. (dd, J PP = Hz, J PH =. Hz, O-P),. (dd, J PP = Hz, J PH =.9 Hz, CH -P). C{ H} NMR (. MHz, C D ): δ. (s, Ar-C),. (s, Ar-C),. (s, Ar-C),. (s, Ar-C),.9 (d, J PC =.9 Hz, Ar-C), 9. (d, J PC =. Hz, Ar-C),. (d, J PC =. Hz, CH ),. (dd, J PC =. Hz, J PC =.9 Hz, C, C(CH ) ), 9. (dd, J PC =.9 Hz, J PC =. Hz, C, C(CH ) ),. (dd, J PC =. Hz, J PC =. Hz, C, CH(CH ) ),. (dd, J PC =.9 Hz, J PC =. Hz, C, C(CH ) ),. (dd, J PC =. Hz, J PC =. Hz, C, CH(CH ),. (dd, J PC =. Hz, J PC =. Hz, C, CH(CH )... Synthesis of ( ipr PCOP)Ir(η -C H ) (). ( ipr PCOP)IrHCl (9;.9 g,. mmol) was dissolved in pentane ( ml) and LiBEt H (. ml,. mmol,. M solution in THF) was added drop wise via syringe under an ethylene atmosphere. The reaction mixture was stirred for min, filtered, and the pentane removed under vacuum to obtain a brownish product. Yield:. g (9%). Anal. Calcd for C H OP Ir: C,.; H,.. Found: C,.; H,.. H NMR ( MHz, p-xylene-d ): δ.9 (d, J HH =. Hz, H, Ar-H),.-. (m, H, Ar-H),. (d, J PH = 9. Hz, H, CH ), nature chemistry Macmillan Publishers Limited. All rights reserved.

12 supplementary information doi:./nchem.9. (t, J PH =. Hz, H, C H ),. (sept. of d, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),.9 (sept. of d, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),. (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),. (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),. (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ) ),.9 (dd, J HH =. Hz, J PH =. Hz, H, CH(CH ) ). P{ H} NMR (. MHz, p-xylene-d ): δ. (d, J PP = Hz, O-P),. (d, J PP = Hz, CH -P). C{ H} NMR (. MHz, p-xylene-d ): δ. (dd, J PC =. Hz, J PC =. Hz, C, Ar-Cipso),. (dd, J PC =. Hz, J PC =. Hz, C, Ar-C),. (dd, J PC =. Hz, J PC =. Hz, C, Ar-C),. (s, Ar-C),.9 (d, J PC =. Hz, Ar-C), 9. (d, J PC =. Hz, Ar-C), 9.9 (d, J PC =. Hz, C, CH ),.9 (t, J PC =. Hz, C, C H ),. (dd, J PC =. Hz, J PC =. Hz, C, CH(CH ) ),. (dd, J PC =. Hz, J PC =. Hz, C, CH(CH ) ),. (d, J PC =. Hz, C, CH(CH ) ),. (s, C, CH(CH ) ), 9. (d, J PC =. Hz, C, CH(CH ) ), 9. (s, C, CH(CH ) ).. Synthesis of ( ipr Anthraphos)Ir(η -C H ) (). To a Kontes flask were added ( ipr Anthraphos)Ir(H)(Cl) ( mg,. mmol), NaO t Bu ( mg,. mmol) and ( ml). This mixture quickly turned a dark-brown/black color and, following freezepump-thaw procedures, was blanketed with an atmosphere of ethylene at ambient temperature. The reaction vessel was closed and the mixture stirred overnight (small scale J-Young NMR tube experiments indicate complete conversion within a matter of hours). After filtration in a glove box, solvent stripping afforded the desired ethylene complex as a very dark (brown) powder ( mg, % yield), which is extremely soluble in all common organic solvents. Satisfactory elemental analyses could not be obtained. nature chemistry Macmillan Publishers Limited. All rights reserved.

13 doi:./nchem.9 supplementary information H NMR ( MHz, CD Cl ):. (s, H, H-);. (d, J H-H = 9.Hz H, H-);. (m, H, H-);. (app t, H, H-);. (vt, H, C H );. (m, H CH(CH ) );. (m, H, -CH(CH ) ). P{ H} ( MHz, CD Cl ):. (s). C { H} ( MHz, CD Cl ):.9;. ( t );. ( t );. ( t );.;.;.;.;. (C H );. (t, -CH(CH ) );. (-CH(CH ) );. (-CH(CH ) ).. Data for dehydroaromatization reactions.. Dehydroaromatization of n-hexane. Table S. Dehydroaromatization of n-hexane catalyzed by, or. a catalyst t (h) trans,trans-,- hexadiene 9 cis,trans-,- hexadiene monoenes others b n-hexane 9 9 TBA a [catalyst] = mm; [n-hexane] =. M; [TBE] =. M; C. c Other unidentified intermediates. nature chemistry Macmillan Publishers Limited. All rights reserved.

14 supplementary information doi:./nchem.9.. Dehydroaromatization of n-octane. Table S. Dehydroaromatization of n-octane catalyzed by, a a or. b catalyst (contn.) ( mm) ( mm) ( mm) ( mm) ( mm) t (h) 9 9 ethyl ortho-xylene total C aromatics cis- and transdimethyl cyclohexane. c mono-, diand tri-ene 9 9 others d n-octane TBA a [n-octane] =. M; [TBE] =. M; C. b [n-octane] =. M; [TBE] =. M; C. c At initial times trans-dimethyl cyclohexane peak overlapped with n-octane peak in GC. d Other unidentified intermediates. nature chemistry Macmillan Publishers Limited. All rights reserved.

15 doi:./nchem.9 supplementary information Table S. Dehydroaromatization of n-octane using propene as hydrogen-acceptor with catalysts or a catalyst t (h) ethyl orthoxylene 9 total C aromatics cis & transdimethyl cyclohexane a 9 mono-,di- & tri-ene othersb 9 n-octane a [catalyst] = mm; [n-octane] =. M in.9 ml mesitylene; P propene = atm ( equiv in -ml reaction vessel); C... Dehydroaromatization of n-decane. Table S. Dehydroaromatization of n-decane catalyzed by or a catalyst t (h) n-butyl 9 9 orthopropyl toluene 9 9 diethyl 9 total C aromatics mono,-di, tri & tetraene 9 others b 9 9 n-decane 9 9 TBA a Conditions: [catalyst] = mm, n-decane =.9 M, TBE =. M, C. b other unidentified intermediates. nature chemistry Macmillan Publishers Limited. All rights reserved.

16 supplementary information doi:./nchem.9.. Dehydroaromatization of n-dodecane. Table S. Dehydroaromatization of n-dodecane catalyzed by or a catalyst t (h) n-hexyl orthopentyl toluene 9 -n-butylethyl ,-di-npropyl 9 99 total C aromatics mono-,di-, tri-, tetraand pentaene 9 9 n-hexane /C olefins others b 9 9 n-dodecane TBA 9 a Conditions: n-dodecane =. M, TBE =. M, [catalyst] = mm, C. b other unidentified intermediates and products.. References S. Przybilla, K. J. & Voegtle, F. Helicale und Planarchirale Pyridinophane Neue Synthesemethodik und Struktur-Chiroptik-Beziehungen. Chem. Ber., - (99). S. Zhu, K., Achord, P. D., Zhang, X., Krogh-Jespersen, K. & Goldman, A. S. Highly Effective Pincer-Ligated Iridium Catalysts for Alkane Dehydrogenation. DFT Calculations of Relevant Thermodynamic, Kinetic, and Spectroscopic Properties. J. Am. Chem. Soc., - (). S. Romero, P. E., Whited, M. T. & Grubbs, R. H. Multiple C-H Activations of Methyl tert-butyl Ether at Pincer Iridium Complexes: Synthesis and Thermolysis of Ir(I) Fischer Carbenes. Organometallics, -9 (). nature chemistry Macmillan Publishers Limited. All rights reserved.